1. Field of the Invention
The present invention relates to a vehicle lighting device.
2. Description of the Related Art
There is a lighting device for a vehicle that includes a projector-type lamp unit using a semiconductor light source, and that is capable of changing a light radiating direction of a light radiated from the lamp unit according to a driving condition of the vehicle, such as a vehicle lighting device disclosed in Japanese Patent Application Laid-open No. 2005-285509. The conventional vehicle lighting device consists of a light emitting diode (LED) and an optical element such as a condenser lens, and is configured such that a plurality of light source modules each having an optical axis extending horizontally in a forward direction are aligned in a lateral direction of the vehicle, the light source modules are connected to each other through a power transmission mechanism, and the power transmission mechanism or one of the light source modules is connected to a rotary driving unit.
The conventional vehicle lighting device is operated in the following manner. When the LED is turned on, a light from the LED is radiated forward. By operating the rotary driving unit, a driving force is transmitted to the light source modules through the power transmission mechanism so that optical axes of all the light source modules rotate in the same direction, changing a light radiation range. Consequently, the conventional vehicle lighting device can be employed for an adaptive front lighting system (AFS), that is, the light radiation range can be changed according to the driving condition of the vehicle.
However, because the conventional vehicle lighting device is of a type in which the LED and the optical element such as the condensing lens are aligned in a row and the light axis extends in the forward direction, the size of the light source module becomes large in the forward direction. Therefore, the conventional vehicle lighting device needs to have a large space sufficient for rotating the optical axes of the light source modules. Thus, there is a limitation in layout of the vehicle lighting device in the positional relationship relative to other vehicle devices and components.